From: Jiawen Wu <jiawenwu@xxxxxxxxxxxxxx>
[ Upstream commit c7b75bea853daeb64fc831dbf39a6bbabcc402ac ]
Clear MV_V2_PORT_CTRL_PWRDOWN bit to set power up for 88x3310 PHY,
it sometimes does not take effect immediately. And a read of this
register causes the bit not to clear. This will cause mv3310_reset()
to time out, which will fail the config initialization. So add a delay
before the next access.
Fixes: c9cc1c815d36 ("net: phy: marvell10g: place in powersave mode at probe")
Signed-off-by: Jiawen Wu <jiawenwu@xxxxxxxxxxxxxx>
Reviewed-by: Russell King (Oracle) <rmk+kernel@xxxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/net/phy/marvell10g.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/drivers/net/phy/marvell10g.c b/drivers/net/phy/marvell10g.c
index df33637c5269a..1caa6d943a7b7 100644
--- a/drivers/net/phy/marvell10g.c
+++ b/drivers/net/phy/marvell10g.c
@@ -307,6 +307,13 @@ static int mv3310_power_up(struct phy_device *phydev)
ret = phy_clear_bits_mmd(phydev, MDIO_MMD_VEND2, MV_V2_PORT_CTRL,
MV_V2_PORT_CTRL_PWRDOWN);
+ /* Sometimes, the power down bit doesn't clear immediately, and
+ * a read of this register causes the bit not to clear. Delay
+ * 100us to allow the PHY to come out of power down mode before
+ * the next access.
+ */
+ udelay(100);
+
if (phydev->drv->phy_id != MARVELL_PHY_ID_88X3310 ||
priv->firmware_ver < 0x00030000)
return ret;
--
2.39.2
